Magneto generator



Sept. 21, .1937. I w SPENGLER 2,093,935

umnmo GENERATOR I Filed May 7,, 1936 3 Sheets-Sheet l INVENTUR.

dcbter' J spalgler' wwwsa= M j se 't.21, 1937. w. J. SPE NGLER-2,093,935

' MAGNETO GENQRATOR Fi led May 7, 1936 a Sheets-Sheet 2 INVENTOR.

Sept 21, 1937.

- w. J. SPENGLER KAGNETO GENERATOR Filed May 7, 1936 3 Sheets-Sheet 3INVENT OR.

MWJW

Ja MW Patented Sept. 21, 1937 v 2,093,935

UNITED STATES PATENT OFFICE MAGNETO GENERATOR.

Walter J. Spengler, Sidney, N. Y., assignor to Bendix AviationCorporation, South Bend, Ind-., a. corporation of Delaware ApplicationMay 7 1936, Serial No. 78,428

' 7 Claims. (01.171-209) The present invention relates to magneto genaresuitably mounted in the frame I as by being erators and moreparticularly to multi-polar gencast therein and are formed at theirupper ends erators for ignition of internal combustion ento receive theprojecting portions of the core 4 gines. of the coil which are suitablyanchored thereto 5 It is an object of thepresent invention to proasbymeans ofcap screws 1 and 8. 5 vide a novel magneto generator adaptedto pro- Referring now more particularly to Figs. 3

vide i it on rrent for a m lti-cylinder-engin and- 4, it will be seenthat the rotor 2 comprises which is eflicient in operation, light,simple and a shaft 9 having a smooth portion II, a squared rugged inconstruction and economical to manuportion [2, a reduced threadedportion IS, a re- 10 facture. Y duced-cylindrical portion H and a stillfurther It s another bjec o Provide such a device reduced cylindricalportion l5.- A cylindrical which is adapted to provide a spark for each45 permanent magnet l6 so magnetized as to have degrees of rotation ofits rotor. its poles at the ,ends of the-cylinder is loosely It isafurther object to provide such a device mounted'onthe squared portionll of the shaft in which the permanent magnet of the rotoriis of and isprovided with polar elements I1 and i8 15 simple construction, requiringVe y little ma-r embracing the ends of the magnet and non-rochining. 1tatably mounted on the squared portion I! of the It is another object toprovide such a device in shaft by means of corresponding squaredopenwhich the rotor is symmetrical in construction ings l9, 2| in theterminal disc elements 22 and and in complete dynamic balance, while thecom- 23 thereof.

ponent parts of the rotor are of simple form and The polar elements l1and I8 are formed of largely interchangeable. laminations of 'magneticmaterial having a It is a further object to provide such a devicerounded polygonal outline forming poles or lobes in which the magneticelements of the stator are 24 and respectively, held in assembled rela-25 rigidly self-supporting prior to the incorporation tion by suitablemeans such as rivets 26. The 25 thereof in the frame Of the agneto andduring openings l9 and 2| in the discs 22 and 23 are the casting of theframe. circumferentially spaced through an angle equal Another Object isto provide such a device in to one-half the side of the respectivepolygons which the rotor and stator are so formed that a so that thelobes 24 and 25 are equally spaced plurality of poles thereof cooperatesimllltaneoiisalternately about the circumference of the rotor. 30

y so a t secure a large r na are As here shown, the polar members I] andis are for the flux paths, while permitting a plura i y formed asrounded squares which are rotated of reversals oi flux therethrough foreach revolue through 45 degrees with respect to each other.

tion of the rotor. The polar members are preferably flared inter-Further objects and advantages will be apnally as shown at 21 (see alsoFig. l), and a cen- 36 parent from the following description taken intering and enclosing ring 28 of non-magnetic connection with theaccompanying drawings in mate'rial is placed between the polar memberswhich: I when in assembled position. Means for confining Fig. 1 is aside elevation, partly broken away, of the polar members on the shaftand compressa magneto embody ng a preferred embodiment ing the magnet l6therebetween is provided in 0 of the invention; i l w the form of anabutment disc 29 adapted to F 2 is a section taken substantially ontheline bear against the shoulder 31 'of the shaft formed 2--.2 of Fig. l;at the junctions of the smooth portion 'II and Fig. 3 is a perspectiveand partially a phantom squared portion l2 thereof, and a secondabutview showing principally the elements composing ment flange 32threaded on the threaded porthe magnetic circuits of the magneto; andtion l3 of the shaft and, retained by suitable Fig. 4 is a perspectiveview of the component means such as pins 33 projecting through theelements of the rotor in disassembled relation and flange into the discs23 as shown in Fig. 1. partly broken away. The stator pole elements 5and 6 are formed Referring first to Fig. 1 of the drawings, there ofsufilcient width, as best seen in Fig. 3, to coopis illustrated amagneto comprising a frame indierate with both the rotor polar elementsI! and cated generally at l having'a rotor 2 suitably I8, and areprovided with pairs of poles 34 and journalled therein and a coil 3fixed therein with 35 respectively, having surfaces concentric with 1its core 4 mounted transversely to the casing as the rotor and spaced soas to cooperate simultabest shown in Fig. 2. Stator pole elements 5 andneously with a pair of polar lobes 24 or 25 of u 7 between the statorpole surfaces 34 and 35 are made of su-mcientdepth to prevent anysignificant amount of flux from passing from arotor lobe to the statorpole element when thelobe is at an intermediate position with respectthereto. It will thus be seen by reference to Figs. 2 and 3 that whentwo of the lobes of one rotor pole element such as lobes 26 of elementil cooperate with the polar surfaces 34 of the stator pole 5, theremaining lobes of that rotor element are spaced from the polar surfaces35 of stator pole member 5; while a pair of lobes of rotor'elementI8vcooperate with the polar surfaces 35 of stator pole 5. so that amagnetic circuit is com- I pleted from the magnet it through a pair ofrotor lobes 25, stator pole member 8, the core 4 of the coil, statorpole member 5 and a pair of rotor lobes 25 back to the opposite end ofthe magnet. Revolution of the rotor through an angle of 45 degreescauses the cooperation of the stator pole members 5 and 6, causing fluxfrompoles to be reversed, whereby the direction of the flux through theexternal magnetic circuit is reversed.

A cover 38 is preferably provided for enclosing the magneto, this coverbeing retained in place by any suitable means such as indicated at 39 inFigs. 1 and 2. I

In the operation of this device, rotation of the shaft 9 from anysuitable source of power derived from the engine to be ignited causesthe lobes of the rotor to cooperate alternately with the the magnet Itto reciprocate through the core of the coil and generate-current thereinin the usual manner.. It will be noted that by reason of the form of therotor elements as rounded squares, there will be eight reciprocations offlux through the coil for each revolution of the rotor whereby themagneto may be used to ignite an engine having 16 cylinders when themagneto is driven at crankshaft speed. It will be obvious that bysuitably shaping the contour of the rotor polar elements, the magnetomay be adapted for the ignition of practically any type of enginewithout the necessity of driving the magneto atundesirably high speeds.

Although but one form of the invention has been shown and described indetail, it will be understood that other embodiments are possible andvarious changes may be made in the design and arrangements of the partswithout departing from the spirit of the invention as defined in theclaims appended hereto.

What is claimed is:

1. In a magneto a rotor including a shaft, a cylindrical permanentmagnet mounted thereon, rounded polygonal polar members non-rotatablymounted on the shaft and providing coaxial seats for the ends of themagnet, means for pressing the polar members on the magnet, and a statorhaving a pair of pole shoes each of which is arranged to cooperatesimultaneously with a plurality of the rounded portions of said polarmembers.

2. In a magneto a drive shaft, a cylindrical magnet mounted coaxiallythereon, a pair of rounded polygonal polar members iixed on said shaft,each cooperating with one pole of said magnet, said polar members beingangularly displaced with respect to each other so as .to uniformlystagger the poles thereof, and a stator aoeaeso .Wth coaxial seats forreceiving the ends of said magnet, said seats having flared portionsextending over the magnet, a centering ring adapted to surround themagnet and enter the flared portions of said seats, and means on saidshaft for compressing the polar elements against the magnet andcentering ring. I

4. In a magneto a rotor comprising a shaft having a polygonal portion,metallic discs having corresponding polygonal openings mounted thereon,a hollow cylindrical magnet mounted on said shaft between said discs,and laminations of magnetic material fixed to said discs having circularopenings adapted to receive the ends of the magnet, said laminationsbeing of rounded polygonal shape to form a plurality of polar lobes.

5. In a magneto a rotor comprising a shaft having a polygonal portion,metallic discs having corresponding polygonal openings mounted thereon,a hollow cylindrical magnet mounted on said shaft between said discs,laminations of magnetic material fixed to said discs having circularopenings adapted to receive the ends of the magnet, said laminationsbeing of rounded polygonalto said discs at each end of the magnet, withthe polar lobes of each group spaced alternately about the periphery ofthe rotor.

6. In a magneto a rotor comprising a shaft having a polygonal portion,metallic discs having corresponding polygonal openings mounted thereon,a'hollow cylindrical magnet mounted on said shaft between said discs,said discs being of rounded polygonal shape forming a plurality ofperipheral lobes, the angular relationship between the lobes and hepolygonal openings of the discs at each end of the magnet beingsymmetrically dissimilar so that said lobes are in staggered relationabout the periphery of the rotor, and laminae of magnetic material fixedto said discs, having circular openings to receive the ends of themagnet and center the same on the shaft, and having peripheral polarlobes.

'7. In a magneto a rotorcomprising a shaft having a polygonal portion,metallic discs having corresponding polygonal openings mounted thereon,a hollow cylindrical magnet mounted on said shaft between said discs,said discs being of rounded polygonal shape forming a plurality ofperipheral lobes, the angular relationship between the lobes and thepolygonal openings of

